A field effect type electron device which is turned on and off in speed higher than a field effect type semiconductor device is proposed in Japanese Patent Kokai No. 4-236466. The field effect type electron device comprises an insulating substrate for providing a bottom wall of an airtight chamber (vacuum) to emit electrons by receiving a light from a light source such as a laser diode, insulating wall members for providing the air-tight chamber cooperative with the insulating substrate for the bottom wall, source and drain electrodes provided on the both sides of the air-tight chamber, and a gate electrode provided on the top surface of the airtight chamber.
In operation, a light emitted from the light source is radiated on the back surface of the insulating substrate.
Thus, electrons are emitted from the insulating substrate into the air-tight chamber, so that two-dimensional electron gas is accumulated in the air-tight chamber. The electron gas is accelerated to be moved with high speed in the air-tight chamber by an electric field generated across the source and drain electrodes, wherein the motion of the electron gas is controlled by an external signal applied to the gate electrode, so that switching operation is carried out with the moving speed of electrons which is 2.times.10.sup.1 cm/s in vacuum by the voltage of 10 V between the source and drain electrodes. This speed is higher than that in the conventional semiconductor device by one digit.
The field effect type electron device overcomes the below listed disadvantages which have been observed in metal wirings for interconnecting highly integrated semiconductor devices.
(1) It is difficult to maintain phases of electrons in a long distance,
(2) The consumption of energy is large,
(3) The delay of signals is large,
(4) Cross talk can not be avoided among interconnections,
(5) Migration is remarkably observed in accordance with the increase of current density,
(6) The function of active devices such as transistors, etc. and that of passive devices such as interconnections, etc. are completely separated to make it impossible that the area of circuits is decreased, and
(7) It is impossible to fabricate an amplifier such as a traveling wave tube, etc. utilizing the direct mutual action between electron and electromagnetic wave, because the moving speed of electrons in metal is slow not to be compared with the speed of electromagnetic wave.
The field effect type electron device has the advantages of overcoming the above described disadvantages.
However, the field effect type electron device has disadvantages as described below.
(1) It is impossible to propagate a plurality of separated electron waves emitted into vacuum in case where only narrow space is available as in a SLSI circuit, because a path of electron wave can not be designated,
(2) Electrons are not distributed uniformly in vacuum, and
(3) Complicated auxiliary devices such as a light source, etc. are required, and the consumption of electric power is therefore large.